Electric heater



w'. c. CALCOTT ELECTRIC HEATER Filed July 5, 1928 van 2.2-

Walter! C, Calc'ait',

\J INSULATlON July 9, 1929.

Patented July 9, 1929.

UNITEDVSTATESV 1,719,872 PATENT OFFICE.

WALTER o. CALCOTT', 0F GARY, INDIANA, ASSIGNOR 'ro soHLEIoHER; me, or GARY,

. INDIANA, A CORPORATION or ILLINOIS.

ELECTRIC HEATER.

Application filed July 5, 1928. Serial No. 290,416.

This invention relates to an electric heater for use as a source of heat in the home or ofiice.

It is an object of this invention to provide an electric heater having unit low ten'iperature heating elements advantageously arranged for insertion of extra units and for eflicient convection heating.

It is afurther object of this invention to provide an electric heater having corrugated metallic ribbon heating elements presenting broad surface exposure-to ascending air currents Without offering substantial resistance to such currents and without tendency to form dead air pockets.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the, accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings:

Figure 1 is an isometric view of an electric heater cabinet with parts broken away to show the arrangement of heating units in accordance with the principles of my invention;

Figure 2 is a top plan View of a heating unit or tray;

Figure 3 is an enlarged sectional view taken on line III-III of Fig. 2; and

Figure .4: is an enlarged fragmentary sectional view taken substantially on line IV-IV of Fig. 2.

The reference numeral 1 indicates a cabinet of a conventional type for enclosing an electric heater of my invention, represented as a whole by the reference numeral 2. Said electric heater comprises one or more heating units in the form of trays 3. Said trays 3 are preferably rectangular in shape and formed of shallow channel stripse, all of the trays being of the same size and shape for positioning one above the other. It is accordingly an easy matter to increase or decrease the number of heating units in any particular cabinet and thus adjust the capacity of the heater to the desired requirements. 1

In each individual heating unit 3 are supported from a pair of end insulation strips 5 and 6 a plurality of strands of resistance wire 7. Said end supporting strips 5 and 6 are mounted from the channel frame 4; by

means of studs 8 and are formedof insulating material. An inside stripof insulation 9 is also fitted Within the channel of the frame 4 and extends around all four sides of said frame. The end supports 5 and 6 are formed with a plurality of spaced upstanding posts 10 provided with a reduced shank portion 11 for receiving the looped strands of resistance wire 7. Atopposite ends on the supporting strip 6 are provided terminal posts 12 and 13 for connection with lead wires 14 and 15 respectively through which current is passed to the resistance wire 7. j v

The resistance wire 7 is formed of closely corrugated metallic ribbon of relatively great width in-comparison to itsthickness. This metallic ribbon is wound about the posts 10 to provide closely spaced parallel strands 16 extending lengthwise of the trays 3 and lying in a generally vertical plane. The broad faces 17 of said strands 16 are thus exposed to the upwardly ascending currents of air passing through the narrow channels 18 formed between said parallel strands. In this Way the maximum amount of surface exposure is obtained without offering material resistance to the upward flow of heated air. Likewise this arrangement of the metallic ribbon heating elements provides for the maximum heating efiiciency where two or more trays 3 are superimposed one upon the other.

The electric heater of my invention is adapted particularly for auxiliary heating since its position in the room or ofiice can be readily changed and its capacity varied to suit the requirements. Furthermore, my electric heaters are intended to be operated at relatively low temperatures so that a large volume of air can be heated without overheating.

the air immediately surrounding the electric heater. The resistance wire 7 is not intended to be raised at any time to a red heat, but merely to a temperature corresponding approximately to the temperature pf a steam radiator.

The efficiency of the heater is made possible through the relatively large surface area exposed by reason of the use of corrugated metallic ribbon for the resistance element and also by reason of the arrangement of the metallic ribbonheat-ing element in a generally vertical plane to provide narrow channels for the upwardly ascending air. V

I am aware that many changes may be made and numerous details of construction may be varied through a Wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art. 7

I claim as my invention:

1. An electric heater comprising a housing, a plurality of superimposed trays disposed therein and heating elements within said trays comprised of metallic ribbon windings forming vertical paths for upwardly ascending currents of heated air.

- 2. An electric heater comprising a housing, a plurality of superimposed trays disposed therein and heating elements within said trays comprised of metallic ribbon windings forming vertical paths for upwardly ascending currents of heated air, said metallic ribbon being positioned in a generally vertical plane upon its thin edge. I

3. In an electric heater, separable heating trays adapted to be. superimposed one upon another and corrugated metallic ribbon heating elementssupported in said trays.

v 4. In an electric heater, separable heating corrugated metallic ribbon heating elements passing around said winding posts to form parallel spaced strands, said ribbon heating elements being of relatively great width and being positioned in a generally vertical plane to present a broad surface exposure to ascending currents of air.

In testimony whereof I have hereunto subscribed my name at Gary, Lake County, Indiana.

WALTER o. GALCOTT, 

